Lower E String is recognized as higher E String

[derhagen]

Tried this with multiple combinations of Microphones and Guitars:

The lower (2nd octave) E string, which is somewhere around 82 Hz is often recognized as the higher (4th octave) E string at > 300Hz. I guess some overtones are involved here. While tuning still works, it is much more unstable and less precise than tuning the other strings.